Electro-magnetic device



. (No Model.) 2 Sheets-Sheet 1,.

G. F. BRUSH. ELEOTRO MAGNETIC DEVICE.

' No. 876,880. Patented Jan. 17, 1888.

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ELBGTRO MAGNETIC DEVICE.

No. 376,630.; Patented Jan. 17, 1888.

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UNITED STATES PATENT OFFICE.

cHAnLns r. nnnsn, or CLEVELAND, 01-110.

ELECTRO MAGNET'IC DEVICE.

SPECIFICATION forming part of Letters Patent No. 376,630, dated January17, 1888.

Application filed December 19, 1885. Serial No. 186,188. No model.)

To all whom it may concern Beit known that I, CHARLES F. BRUSH, ofCleveland, in the county of Ouyahoga and State of Ohio, have inventedcertain new and useful Improvements in Electro-Magnetic Devices; and Ido hereby declare the following/to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart towhich it appertaius to make and use the same.

My invention relates to an'improvement in electromagnetic devices.

Under certain circumstances it is desirable to arrange anelectro-magnetic device in such manner that a temporarily abnormalcurrent will not cause the device to respond, even though suchtemporaryincrease may be beyond a predetermined point, where acont-inuous abnormal current will result in the functional act-ion ofthe device. This I believe has not hitherto been accomplished. Forinstance, if there be included in a circuit of arc lampselectro-niagnets whosearmatures are adjusted to respond to a certainstrength of current, and it the supplying current be started suddenly,an abnormal flow of current will result, owing to the fact that thecarbons of the lamps are in contact and the resistance of the externalcircuit therefore low. This abnormal current, though temporary, may beof astrength sufficient to cause the electroniagnets to attract theirarmatures, which, in the cases under consideration, is not desirable.

The object of my invention is to overcome the above difficulty, howevercaused, and I accomplish it by mechanism shown in the accompanyingdrawings, Figure 1 of which shows, partly in section, one form of myin-Fig. 2 illustrates the invention as embodied in a multiple seriescut-out.

A is an electro-magnet whose coil forms part of a circuit, B B.

Gis an armature pivoted at D in such a manner that the end of thearmature toward the electro-magnet and directly under its influence willbe considerably heavier than the otherend.

E is a cylinder closed at its upper end and open at the lower. Aplunger, F, fits nearly airtight in the cylinder and projects from thelower end. The bottom of the plunger is rounded and rests normally onthe remote end of the armature. The weight of the plunger is such thatwhile, when resting on the armature, it assists to overcome thepreponderance of the heavier end, it does not do so entirely. A pin, G,fastened to the plunger F projects through the side of the cylinder, andworking in a vertical slot, H, limits the vertical motion of theplunger. The cylinder at its upper end is attached rigidly to the rod K,which passes through a hole in the lug L, which is securely fastened tothe frame-work (a portion of which is shown at Z) of the apparatus. Thecylinder is adjustably supported by means of a setscrew, M, passingthrough the lug and impinging on the rod K. This adjustment, it will beseen, serves to determine the position of the armature.

The action is as follows: I will assume, for the purpose ofillustration, that the electromagnet is in a circuit of are lamps fed bya dynamo-electric machine, and that the distance of the armature fromthe magnet has been suitably adjusted. 7 If no current be flowing,theparts will bein the position shown by the continuous lines in thedrawings, the plunger F being at its highest position from thepreponderance of the magnet end of the armature. If, now, the normalcurrent be sent through the circuit 13 B, the magnet will attract thearmature, and the latter will move up toward the magnet, but at a ratelimited to the motion of the plunger, which, being nearly air-tight,drops slowly, dash-pot fashion, andif the armature attempt to movefaster than the plunger drops the magnet is then deprived of theassistance of the weightof the plunger, and as the relations of theweights and distances are suitably proportioned the magnetis unable toraise the dead-weight of the armature alone. Consequently when theplunger has descended to its lowest point, as shown by the dotted lines,the weight of the plunger is borne by the pin G, resting on the bottomof the slot H in the cylinder, and the armature will make no furthermovement except under the influence of an increased current to which itis set to respond. If, now, the current be temporarily stopped, as bythe flashing of the machine,

the carbons in the are lamps will all in a few seconds have cometogether and again complete the circuit, causing an abnormal flow ofcurrent until the ares have been reestablished.

The action of my improved apparatus,under these and the similarcircumstances above indicated as due to the sudden starting of themachine at full speed, will be as follows: \Vhen the current is stopped,the electromagnet will become inoperative and the armature will fallback, raising the plunger to its highest point, This will occur in thecase of flashing while the carbons of the lamps are feeding intocontact.- Then upon the reestablishment and consequent abnormal flow ofcurrent the armature will be attracted and the plunger commence todescend; but owing to the slow movement of the plunger, as aboveexplained, before the armature can get to a position where it would beraised completely by the magnet, under the influence of the increasedcurrent, the abnormal flow of current will have ceased, the normalarcsin the lamps having become established.

It will of course be understood that the movement of the armature whenfully attracted by the magnet may be utilized to perform any desiredfunction The magnet A may be located in a shuntto some electro-reeeptivedevice or devices operated by a main current.

In Fig. 2 I have shown the invention as applied to a multiple seriescut-out, in which a is the supporting-frame having two insulatedbinding-posts, b c, fastened thereto. One end of the main circuit B issecured in the post 0. Incandescent lamps or other electro-receptivedevices, (I, are included in the branch circuits 0, which latter areconnected at their opposite ends to the conductor f, the opposite endsof which are connected, respectively, to the binding-posts b c.Electro-magnetg is wound with two coils, h and t, the coil h beingofhigh resistance and forming a constantly-closed shuntcircuit aroundthe group of incandescent lamps or other clectro-rcceptive devices, (I.The other coil, 2', is of coarse wire, and has one of its terminalsattached to a conductor, i", which is connected to the binding-post c,and its other terminal, 1, forming a contact, I, which is located inclose proximity to the lower end of the conductor 6, attached to thebinding-post Z). The terminal 2' serves as a spring-contact, and isnormally out of contact with'the end of conductor i. An armature, G, ispivoted at d, the end Z, located beneath the electro-magnet, beingconsiderably heavier than the opposite end, Z. The plunger F rests uponthe end Z of the armature and operatesin the mannerhereinbeforedescribed.

The operation of the multiple series cutout is as follows: \Vhen thelamps d d, &c., are in operative condition, the normal current on theline B B will divide itself between the lamps (Z, excepting the smallpercentage of current which will pass around the group by theshunt-circuit, including the fine-wire coil It. Should a number of thelamps (Z become inoperative from any cause, the increased currentdiverted through the fine-wire coil it will energize the magnet gsufficiently to raise the armature O and cause the latter to force thecontact I into engagement with the lower end of the conductor 2", andthus form a shunt-circuit of low resistance around the group of lamps,through which low-resistance shunt the current will be diverted. As thislow'resistance circuit has the coarse-wire coil of the magnet includedtherein, the current flowing through it, when the circuit is closed,will augment the strength of the magnet g, and thus hold the armaturefirmly in its raised position. In order to prevent the armature C fromresponding to an abnormal flow of current of short duration, due to thecauses specified, or to any other, and which would operate to cut outthe group of lamps d, I provide the cut-out with the plunger attachment,which causes the armature to rise so slowly that the abnormal flow ofcurrent will have ceased before the armature can rise to a positionwhere it could be completelyraised by the lifting power of the magnet.Thus the cut-out will automatically switch out of circuit the group oflamps d whenever a predetermined number of them should fail to operate,but will not respend to an abnormal flow of current of short duration,and thereby accidentally switch the group of lamps out of circuit. Thecut-out is provided with a switch-lever, S, for manually switching outof circuit the group of lamps d.

Fig. 2, and the descriptive matter relating thereto, is incorporatedherein simply to make compliance with the request of the Patent Ofiicethat some practical embodiment otthe invention should be disclosed; butby this disclosure I do not relinquish any right to claim anysubject-matter of invention that may exist in the device illustrated inFig. 2, and reserve such right for a separate application.

I do not limit myself to the special construe tion or arrangement ofparts shown.

Having fully described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. The combination, with a helix included in an electric circuit and anarmature, of a supplemental actuating device constructed and arranged tooperate slowly through a predetermined distance and assist the helix inmoving the armature gradually to a predetermined distance from the helixand then to release the armature to the sole action of the helix,substantially as set forth.

2. In an electromagnetic device consisting primarily of. anelcctro-magnet and an armature controlled thereby, a dash-pot, themoving portion of which, without being connected, except by simplecontact, with the armature or moving parts attached thereto, assists thearmature, during it portion of its movement, I I In testimony whereof Ihave signed this to respond to the attractive influence of thespecification in the. presence of two subsoribmagnet but at alimitedrate of motion, the ing witnesses.

position of said movable portion .of the dash- CHAR-LES F. BRUSH. potbeing controlled by said armature when XVitnesses: not under theinfluence of the magnet sub- ALBERT E. LYNCH,

stantinlly as setforth. L. B. LE VAKE.

